A bit more explicit if statement

src/Nmap/Nmap.php

@@ -58,7 +58,8 @@ public function __construct(ProcessExecutor $executor = null, $outputFile = null
         $this->outputFile = $outputFile ?: sys_get_temp_dir() . '/output.xml';
         $this->executable = $executable;
 
-        if ($executor->execute($this->executable)) {
+        // If executor returns anything else than 0 (success exit code), throw an exeption since $executable is not executable.
+        if ($executor->execute($this->executable) !== 0) {
             throw new \InvalidArgumentException(sprintf('`%s` is not executable.', $this->executable));
         }
     }